Structure of PDB 4s26 Chain A

Receptor sequence

>4s26A (length=519) Species: 3702 (Arabidopsis thaliana)

PSSPDFQPIPSFEECFPKSTKEHKEVVHEESGHVLKVPFRRVHLSGGEPA
FDNYDTSGPQNVNAHIGLAKLRKEWIDRREKLGTPRYTQMYYAKQGIITE
EMLYCATREKLDPEFVRSEVARGRAIIPSNKKHLELEPMIVGRKFLVKVN
ANIGNSAVASSIEEEVYKVQWATMWGADTIMDLSTGRHIHETREWILRNS
AVPVGTVPIYQALEKVDGIAENLNWEVFRETLIEQAEQGVDYFTIHAGVL
LRYIPLTAKRLTGIVSRGGSIHAKWCLAYHKENFAYEHWDDILDICNQYD
VALSIGDGLRPGSIYDANDTAQFAELLTQGELTRRAWEKDVQVMNEGPGH
VPMHKIPENMQKQLEWCNEAPFYTLGPLTTDIAPGYDHITSAIGAANIGA
LGTALLCYVTPKEHLGLPNRDDVKAGVIAYKIAAHAADLAKQHPHAQAWD
DALSKARFEFRWMDQFALSLDPMTAMSFHDETLPADGAKVAHFCSMCGPK
FCSMKITEDIRKYAEENGY

3D structure

• PDB: 4s26 Non-canonical active site architecture of the radical SAM thiamin pyrimidine synthase.
• Chain: A
• Resolution: 1.85 Å

Enzymatic activity

• Enzyme Commision number: 4.1.99.17: phosphomethylpyrimidine synthase.

Interaction with ligand

Site #	Ligand	Ligand chain	Binding residues on receptor (original residue number in PDB)	Binding residues on receptor (residue number reindexed from 1)	Binding affinity
BS01	SF4	A	W538 C570 M572 C573 C578 S579 M580	W462 C494 M496 C497 C502 S503 M504
BS02	IRN	A	N228 M257 Y286 H322 S342 R343 G344 D383 R386 E422 G423 L451	N152 M181 Y210 H246 S266 R267 G268 D307 R310 E346 G347 L375
BS03	SAH	A	N228 I229 G230 L259 V341 R343 R386 H426 E489 H490 L493	N152 I153 G154 L183 V265 R267 R310 H350 E413 H414 L417
BS04	ZN	A	H426 H490	H350 H414

Gene Ontology

Molecular Function

• GO:0016830 carbon-carbon lyase activity
• GO:0051536 iron-sulfur cluster binding

Biological Process

• GO:0009228 thiamine biosynthetic process

External links

• PDB: RCSB:4s26, PDBe:4s26, PDBj:4s26
• PDBsum: 4s26
• PubMed: 25813242
• UniProt: O82392|THIC_ARATH Phosphomethylpyrimidine synthase, chloroplastic (Gene Name=THIC)